what do you think about this box design for a alpine swr1242d 12 "http://subwoofertools.com/forum/ported-box.asp?Ew=25&Eh=13.5&Dia=6&Xmax=18.2&Vd=0.071&NumW=1&Vb=&Fb=35.03&Qts=.47&Vas=1.6&Fs=29&CE=1.5 please copy paste this page and give me some opinions about what to expect for the sound above the tunning frequency